If you are an early morning riser, the beginning of the week has a planetary show in store for you while Fall official begins on Friday with the Autumnal Equinox, and Acadia Night Sky Festival returns Thursday to Sunday. For more on the Festival, see here. Here is your guide to the sky for September 18 to 24, 2017…

Acadia Night Sky Festival 2017

Morning Planetary Sights…

If the skies are clear, it will be worth getting up early on Monday morning before dawn to see a beautiful gathering of the waning crescent Moon with Mercury and Mars. These three solar system bodies appear less than half a degree apart (about the size of the Full Moon) low in the eastern sky. Higher above the horizon, check out bright Venus which will be half a degree from the bright star Regulus in Leo the Lion on Tuesday morning. Evening viewers get treated to Jupiter and Saturn. Jupiter is low in the western sky setting around 7:30 pm while Saturn in the southwest as sunset is visible until around 10:15 pm. Friday early in the evening look for a new waxing crescent Moon four degrees south of Jupiter. While Cassini ended its mission to Saturn this past Friday, the Juno mission to Jupiter is still in full swing. Both spacecraft have revolutionized our understanding of the two largest gas giants in our solar system and the data they have gathered will be analyzed for years to come.

Planets the Morning of September 18 before sunrise

Autumnal Equinox and New Moon

New Moon takes place Wednesday morning at 1:30 am. The Sun has been active recently with a couple large flares producing some good aurora a bit over a week ago. Sunrise around 6:20 am and sunset around 6:30 pm for this week. The Autumnal Equinox (here in the Northern Hemisphere) is on Friday at 4:02 pm. This is the point in our orbit where both hemispheres get an equal amount of sunlight. Here in the Northern Hemisphere it signals the official first day of Fall, while in the Southern Hemisphere they are transitioning to Spring. Equinox mean “equal night” as the amount of daylight and night should be equal. Our days now here in the Northern Hemisphere will begin getting shorter and shorter as we move toward the Winter Solstice – the shortest day/longest night of the year. Our weather this past week has been much more summer like, but fall is coming and soon our leaves will change, the weather will cool, and birds will start migrations south. The seasons march on and it is wonderful to celebrate the changes they bring us!

A Baseball Diamond in the Sky, or Pegasus a horse of course…

Stargazing in fall skies means looking for the baseball diamond in the sky, or Pegasus the winged horse of course! Now constellations are imaginary connections of stars similar to connecting dots, but in some cases like Orion the Hunter, or Scorpius the Scorpion the stars provide at least a reasonable outline for drawing these figures. Pegasus is a bit hard to imagine as a horse, winged or otherwise, given the main stars really form a perfect square or diamond shape. At 8pm look about 15 degrees above the horizon to see these stars. If you need help, almost straight overhead is the Summer Triangle of Vega, Deneb, and Altair. If you imagine it as an ice-cream cone, imagine the ice-cream falling off to the east and you should be able to find the square. Flying horse or not, this group is fun to find in the night sky, and if future posts we will explore its connections to other fall constellatons.

With Autumn beginning, morning planets, and a flying horse to make you wonder how the ancients saw this mythical creature with a square of stars, there is always something to observer. The Clark Telescope is now open on Friday evenings following public planetarium shows at Emera Astronomy Center (weather permitting) to provide telescope views too – so check it out when you have a chance. Keep your eye on the sky!

About Shawn Laatsch

Shawn Laatsch is the director of the Emera Astronomy Center and Jordan Planetarium at the University of Maine. He started his astronomy education career in 1984 and has directed planetariums in university and science center facilities, taught undergraduate astronomy courses, and given numerous lectures around the globe. He serves as President (2017 & 2018) of the International Planetarium Society, Inc. the world’s largest organization of planetarium professionals. Shawn has a passion for sharing astronomy and stargazing with people of all ages.

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Shawn Laatsch

Shawn Laatsch is the director of the Emera Astronomy Center and Jordan Planetarium at the University of Maine. He started his astronomy education career in 1984 and has directed planetariums in university and science center facilities, taught undergraduate astronomy courses, and given numerous lectures around the globe. He serves as President (2017 & 2018) of the International Planetarium Society, Inc. the world’s largest organization of planetarium professionals. Shawn has a passion for sharing astronomy and stargazing with people of all ages.